Enter the travel length (m) and the slope into the Calculator. The calculator will evaluate the Time of Concentration.

## Time of Concentration Formula

tc = .0078*(L^..77/S^..385)

Variables:

- tc is the Time of Concentration (minutes)
- L is the travel length (m)
- S is the slope

## How to Calculate Time of Concentration?

The following steps outline how to calculate the Time of Concentration.

- First, determine the travel length (m).
- Next, determine the slope.
- Next, gather the formula from above = tc = .0078*(L^.77/S^.385).
- Finally, calculate the Time of Concentration.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

travel length (m) = 9

slope = 10